Process of making pumps



P. L. SCOTT PROCESS OF MAKING'PUMPS riizinu Filed Dec. 15,1919

June 15,1926. 1,589,240 I 6 v '1 I V r C [Wk/5 72 to?" Witness f/zz'Zz'pl ficotzf.

Patented 'June 15, 1926.

UNITED STATES PATENT oFFicE'.

PHILIP LANE scor'r, or CHICAGO, rnLrNors'assreNon'ro sornn-n'msnx.raaozron CORPORATION, or LA ronrn, INDIANA, A CORPORATION. or NEW YORK.

rnoonss or MAKING ruins.

Original application filed December 15, 19 19, Serial No. 344,883.Divided and this application filed December 15, 1920, Serial No.430,825. Renewed January 6, 1926.

My invention relates to improvements in process of making pumps. Amongthe ob jects of my invention are to provide a pump in which all workingparts are properly lubricated and in which leakage is prevented.

Another object is to provide a pump.

wherein the clearances will be sufiiciently minute to permit pumping tobe done by piston or plunger without any packing and Without disastrousleakage. 1

In connection with carrying out my .invention, I find that preferablyone ofrthe wearing surfaces either the plunger of seat ought to be softiron and the-other of steel.

At least, one ought to be harder than the other, although this is notabsolutely essential;

It may be saidiin this connection that.

one'reason why cast iron is satisfactory for this purpose is that eventhough the soft iron warpsand develops in pumps lumps and distortionswhich engage the plunger, these irregularities are immediately worn downwithoutsticking. If bronze were used, we

would have bindingof the piston as soon as any appreciable distortionhas taken place. Other objects will appearfrom time totime in thespecification.

.My pump,,in the form here illustrated, is

particularly designed for'use with direct injection hydrocarbon internalcombustion engines, where high pressures are ,used. It

may, however, be adapted to a variety of other uses, forexample'wherever -apump is required. One form is illustrated in sectionin the accompanying figure, wherein A is a jacket impervious to oil, andin the form here illustrated, 'is made'of steel.

' B is an inner liner of such material that 9 the oil may penetrate init and through it, and which is of such a character that it fula .fillsthe requirements above pointed out in connection with the closeclearances and fits required. In this cas'e, it ismade of cast 5 iron. Bis a bore in the liner B and en larged' at B to provide. an oil pocketor chamber. B isa bore'inthe side of the liner B and extendingthroughthe jacket A. B is another bore in the linerB, extending throughthejacket A. t

C is an v1 let connectl into the bore B ofthe jacket A. It has thecentralbore C which is enlarged at C and prov. dedwitha beveled valveseat C upon positioned.

on, screw-threaded This double valve arrangeuicnt constitutes the inletside of thepump.

D is a discharge connection, screwthreaded into the jacket A in the boreB It has the central bore D which terminates at one end in the beveledface D against which the spring D abuts. D is a packing. D is a valvesleeve having the pocket D in which is the beveled valve seat D. D is avalve adaptedto be seated on the valve seat by the spring D. D is'anarrowed bore in the valve sleeve in'which the valve D -is D are vaneson the valve adapted to contact the sides of'the bore and to cause theproper seating and alignment of- 'the valve.

E is a plunger having the enlarged head E E is a collar secured on thehead. E is a springabutting at one end against the liner B and at theother against the collar E The pump may be driven by any suitable meanssuch as a cam or rocker arm, not here shown, forming no part of thisinvention. Thereis theadditional feature of lubrication due to theporous quality of the iron.

It has beenfound in practice that the oil will work through the iron andback along the piston through its entire length. This results in a filmof'oil entirely surrounding the piston throughout its lengthand'thoroughly 'lubrica'tingit without the medium of any additionalchannels or passages.

In my apparatus, I do .not know exactly what the clearances are betweenthe-plunger. and the plunger seat. They range probably somewhere in theneighborhood of a ten-thousandth of an inch. The reason why I do notknow what the clearances are is because the parts are made originallywith practically no clearance except that necessary to make it possibleto force the lunger into the seat with a pressure. of rom 15 lbs. up,the plunger and seat being lubricated and then reciproeated withreference one to the. other and thus being la ped in.

together with an oil tight wbrking t Without the use of any abrasivematerial. 1,

lOO

or similar types of engine although it may be-used for pumping anyliquid.

It is an interesting fact in connection with this particulararrangementof vpump and bearing surface, that when the p1l1n1)1S properly made, wehave a"pump in which the plunger is actually freer to reciprocate thanit wouldbe the normal type ofstufi'- ing box were used and thischaracteristic is one of the essential or at least exceedingly the pumpsmooth and responsivein'its action.

\ Vhen the plunger and the bearings are fitted as I have abovesuggested, theirrelation is such that the plunger will be suspended orcentered in'the; seat by a very thin film of oil and this film ispreferably so thin that the surface tension of the oil is sufficient toresist the shearing action resultant from the movement of the plungerwith respect to the seat even though the pressures are ,very great, andthis gives us a continuousoil film so that there .is a negligiblefrictional resistance to the movement of the plunger and it is thissurface ten- .sion also which probably prevents, or is largely active inpreventing any leakage between the plunger andthe seat. This is sharplyvcontrasted with any arrangement where a stufiing box is used because thestuffing'boxhas for its characteristic that it tends to break the oilfilm thus increasing the resistance to the movement of the plunger andalso doing away with'any benefit which maybeobtained from the surface 7tension-resisting the leakage.

It will. be understood that as the pump warms up to its work it developsa sensi ble heatwhich may be variable, andas aresult of this thediameter of both the plunger and the seat changes in different ratios.[In order that leakage may not take place during normal operation, it isneces- 'sary that theplunger must expand more than the barrel, andtherefore one'o'f the members, either the plunger orithebarrel, must becapable of wearing away sufficiently to produce such a fit as willsatisfy the necessary conditions of permanent operation.

The 5 and operation of my invention are as follows 2- When the pistonis. drawn out by the spring a suction is produced and the two valves onthe suction side are opened by it against the pressure 'of theirsprings. By I this means oil is drawn into the pumping-- chamber. Whenthe piston is forced back charge valve isunseated by it, and the liquidAs the movement otthe piston continues, pressure is created and thedisisforced out throughthe discharge con-- nection,

1 find that the close fits provided make leakage along the plungerpractically impossible'and it is a fact that a pump handling upwards of400 cubic inches of oil per hour at-pressures ra'ngingfrom 3000 to 8000lbs. per square inch, will not leak more than a few' drops of oil pastthe plunger during an hour'period. -In fact there is less leak vention,and I wish therefore, that my drawings be regarded as in a sense diasgrammatic. What I claim 1s- 1. The processof manufacturing" a pump whichconsists in forming a cylindrical seat, and a unitary plunger of su samediameter lnsertmg the plunger 1n the stantially the r. age than on anystufiing box, that could important characteristics because it makes seatand forcing it in under pressure, then reciprocating one of the partswith respect to the other until a smooth working oil-tight fit isobtained. Y

2. The process of manufacturing a pump which consists informing acylindrical seat, and a unitary plunger of substantially the samediameter inserting the plunger in the seat and forcing it in underpressure, then reciprocating one of the parts with respect to the otheruntil a smooth working oil-tight fit is obtained without introduction ofany abrasive material.

3;, The prooessof manufacturing a pump which consists in forming acylindrical seat, and a plunger of substantially the same diameter,one'of-them' being of softer" material'thanthe other, inserting theplunger in the seat-and forcingit in under pressure,

then reciprocatingone of the parts with're- 7 spect to the other until asmooth' working oil-tight fit is obtained. 4 I 4. The process ofmanufacturing a pump which consists informing a cylindrical seat and-anuncompressible plunger Ofsubstan 'tially the same diameter, insertlngthe plunger in the seat, forcing-it in under pressure, thenreciprocating one of the parts with respect to the other until a 'smootworking oil-tight fit is obtained. i 5. The process of manufacturing aump which consists in forming a cylindrica seat "and an'uncompressibleplunger of substantially the same diameter, insertingthe plunger in theseat, forcing it in under pressure, then reciprocating one of the partswith respect to the other until a smooth Working oil-tight fitisobtained, Without theintroduction of any abrasive material. 7

6. The process of manufacturin a pump which consists in forming a cylinrical seat and an uncompressible plunger of substan-- vwhich consists informing a cylindrical seat and an uncompres sible plunger of substantially the same diameter, lubricating the parts, inserting the plungerin the seat, forc- 1t i-n underQpressure, then reciprocating one of theparts with respect to the other until a smooth'working oil-tight fit isobtained,

Without material.

8. The process of manufacturing a pump which consists in forming acylindrical seat,

the introduction of any abrasive and aplungerof substantially the samediameter, the seat bein of softer material than the plunger, insertingthe plunger inthe seat and forcing it in under'pressure', thenreciprocating one' of the parts with respect to the other untila smoothworking oil-tight 4 fit is obtained. f I Signed at Chica 0, county ofCook and State of Illinois, t is tenth day of December, 1920. 1 'oPHILIP LANE SCOTT. 1

